Figure 11

Evolutionary development of kinetochores from yeast to mammals. (a) Model of the kinetochore using protein subunit positions derived from the organization of the S. cerevisiae kinetochore. Proteins present in all fungal and mammalian CENs are outlined in black while proteins present only in fungi and mammals with regional CENs are outlined in red. Red dotted outlines indicate proteins that are only present in fungi. Black dotted outlines indicate that either this protein only exists in metazoans or that only the metazoan ortholog is present at kinetochore. Proteins colored in pink, blue, green or yellow represent components of the DNA binding, linker, regulatory or microtubule-binding layers, respectively, based on kinetochore organization in S. cerevisiae. Potential multi-protein complexes are highlighted with a light gray box and the conserved kinetochore core, or COMA/Sim4 adaptor with a dark gray box. Protein names are given for H. sapiens first and then S. cerevisiae when different. Italic lettering indicates that the protein has additional functions in the cell. The kinesins present at kinetochores in H. sapiens are CENP-E (Kinesin-7) and MCAK (Kinesin-13), and in S. cerevisiae Kip3 (Kinesin-8), Cin8 (Kinesin-5), Kip1 (Kinesin-5) and Kar3 (Kinesin-14) (for nomenclature see [38]). (b) Quantification of the number of kinetochore proteins, and their respective evolutionary class, in S. cerevisiae, S. pombe, E. cuniculi and H. sapiens.